GRE provides advanced file management capabilities, similar to those of other sophisticated Windows-based programs. The user can drag and drop a setup onto GRE and GRE will open it. At the click of a button, the user can create a new setup, open another setup, save a setup, save all setups, or revert to the saved version of a setup.
GRE also maintains a list of the most recently opened setups, and the user can reopening any of these setups simply by choosing from the list on the File menu.
One of GRE's niftiest features is the ability to copy gearbox settings from one setup to another, while leaving the chassis settings intact. GRE can also do the opposite, copying in chassis settings while leaving the gearbox settings intact.
This feature can facilitate rapid adaptation of setups from one track to another or one chassis to another. For example, since all Advanced Trainers use the same engine, a Ferrari setup for Kyalami could be quickly assembled by copying the gearbox settings from a Brabham setup for Kyalami into the chassis settings for the Ferrari at Zandvoort.
Once you've got a baseline setup for each chassis, and have gearbox ratios for the Trainers at each track, in seconds you can produce an initial setup for any chassis at any road or street circuit.
GRE incorporates extended ranges for Bump Rubbers, Spring Rates, and Anti-Roll Bar Rates. GRE allows shorter bump stops than GPL allows, and permits higher spring rates and anti-roll bar rates as well.
Here's why:
GPL simulates 1967 Formula 1 cars. However, thanks to the dedicated work of David Noonan, we now have available conversions of many of the ovals used by CART, the IRL and NASCAR. [David Noonan's converters are available in the GPL section of The Pits.]
At this writing, it appears that GPL and the conversion ovals are the closest thing we'll get for some time to a CART simulation based on the GPL physics engine.
Unfortunately, GPL's suspension parameters, which are designed for road courses, don't allow springs and anti-roll bar rates that are appropriate for steeply banked ovals. The vertical loads generated by the high-G turns at tracks like Charlotte, Atlanta, and Bristol are too high for the wheel rates GPL permits. The car winds up running on its bump rubbers throughout the corners.
To facilitate development of historically correct - and effective - setups, GRE permits higher spring rates and anti-roll bar rates. This allows setups which work properly even on the steepest bankings.
We feel that this is equivalent to calling up Colin Chapman or Dan Gurney and ordering the bits necessary to run your car on the American ovals. Since a variant of the Eagle T1-G in GPL actually did run the ovals, and the Lotus 49 is closely related to the Lotus cars that ran at Indy in 1965 and 1966, we feel that permitting such spring rates is historically appropriate as well as practical.
Throughout the last 10 months of GPL's development period, GPL allowed .5 inch bump rubbers (also known as bump stops). However, GPL's tracks do not model the high-frequency bumps that exist in real life tracks.
GPL also does not provide an audible warning when its suspension bottoms, as a real car does.
These factors combined to permit unrealistic extremely low setups, setups which would never work in real life. The result was cars that were unrealistically difficult to drive, and which contributed significantly to GPL's reputation for being "difficult to drive".
Concerns about ultra-low "lowrider" setups prompted Papyrus to change the minimum bump rubber length from .5 inches to 1 inches shortly before GPL's release.
We feel that this change is a kludge to cope with the problem with track modeling and the lack of audible feedback. A much better solution (although arguably still a kludge) is incorporated in GPL 1.2 (a patch available for free from Papyrus). This version of GPL restricts ride height to a minimum of 2.5 inches, thus much more effectively preventing unrealistic "lowrider" setups.
Longer bump stops increase the likelihood of GPL's rear suspension bottoming in high-download situations, such as banked corners, the bottom of dips, over large bumps, and under hard acceleration. Any combination of these factors further increases this likelihood.
When the rear suspension bottoms, there is an immediate transfer of weight away from the inside wheel and to the outside wheel. This results in an almost instantaneous transition to oversteer ("snap" oversteer).
This makes GPL much more difficult to drive. Almost all default setups included with GPL, and the vast majority of setups available on the Internet, allow the rear suspension to bottom at several places at almost every track.
The driver has no audible warning of this bottoming. It presents itself as a sudden, inexplicable transition to oversteer. This snap oversteer is one of the principle factors in GPL's reputation as being "difficult to drive".
Worse, it's not realistic. In real life, in 1967 the teams did not run their cars on the bump stops. (This did not become common practice until the advent of wings, which gave high downloads which in turn led to long, soft bump rubbers - and rising rate suspension - to keep the chassis off the track at high speeds.) John Cooper, in a recent interview with a GPL enthusiast, stated that their practice at each circuit was to lower the car until its suspension bottomed, and then raise it just enough so it wouldn't bottom. (Certain tracks, such as the Nurburgring, are obvious exceptions.)
Given this, it's fairly clear that the 1 inch bump rubbers in GPL are too long. The value used during most of GPL's development period was historically correct. Given GPL's maximum available rear spring rates, with 1 inch bump rubbers it's necessary to run at higher than realistic ride heights at almost all tracks to avoid bottoming the suspension. After extensive testing, I've concluded that with 1 inch bump rubbers even the lightest cars require ride heights close to 4 inches to avoid bottoming - at almost every track!
Shorter bump rubbers permit more realistic setup heights. Therefore, GRE permits shorter bump rubbers.
GRE provides a number of helpful features intended to assist in perfecting and fine-tuning setups.
By default, GRE displays the entire setup, including all gearbox and chassis parameters. The user can choose to view only the gearbox settings, or only the chassis settings. This facilitates comparison of different setups and helps users with smaller monitors to view setups more easily.
To
assist in developing the gear ratios for each setup, GRE provides
a graph showing the speed in redline for each gear (assuming the
car could actually reach redline in that gear). This graph also
shows a band in which the engine is producing at least 90% of
its maximum torque, and another band for 90% or more of its maximum
power.
At the click of the Show Graph button, GRE also will display a chart for the engine's torque and power curves.
Also, as a convenience, when the Redline in 5th field is adjusted, all gear ratios are also adjusted in the same direction.
GRE has a Notes section which saves any notes you wish to take in a text file with a name similar to that of your setup. This is an enormously useful feature, as it allows you to note what your fast time with the setup was, your impressions of it, how it might be improved, or whatever other useful information you have that you'd like to associate with that setup.
GRE has a built-in spring weight distribution calculator and shows each chassis' weight distributions front to rear. This provides a quick reference for getting the spring weights correct with relation to the car's weight distribution. The user can elect to lock spring rates to weight distribution, so that increasing or decreasing one end's rates will automatically increase or decrease the other end's rates as well.
GRE also allows the user to elect to force front and rear spring rates to remain in a fixed relationship with one another. This can be useful when adapting a setup to a track that demands higher spring rates, such as from Milwaukee or Gateway to a more steeply banked oval or from a normal road course to a circuit like the Nurburgring. It can also be useful going the other way, from a vertically demanding circuit like Zandvoort to a virtually flat circuit like Long Beach.
The GRE user may elect to lock anti-roll bar rates to a fixed total. This is useful when fine tuning the balance of the car; the user can conveniently adjust the bars to provide more oversteer or more understeer without impacting the overall roll resistance of the chassis.
Since a change in the overall roll resistance could impact camber settings, spring rates, or ride height settings, it can desirable to be able to avoid such changes when in the fine-tuning stage of setup development.
GRE permits the user to make adjustments to many of the settings in finer increments than those provided for GPL. This can permit the user to, for example, set the spring rates in precise proportion to weight distribution, or make small adjustments to camber, caster, ride height, bump rubber length, and many other parameters.
Unfortunately, GPL itself doesn't accept finer adjustments to the damper settings, which is one of the areas where we'd most benefit from this capability!
Like GPL, GRE makes estimates of fuel requirements based on the consumption numbers for the AI cars in the track.ini file for each track. However, GRE makes what we believe are more realistic estimates for the GP cars, based on over a year of experience in racing the cars.
GPL doesn't adjust the fuel requirements for the Trainers, so if you follow its estimates you'll generally have too much fuel in the Trainers. GRE does adjust for the Trainers' reduced horsepower and therefore reduced fuel consumption, however, so its fuel requirement numbers for the Trainers are much more useful.